The book begins with fossil record of cyanobacteria and gives comprehensive treatment of antibacterial activity of cyanobacteria based on extensive research done by the authoIt also highlights the other aspects of biological activity like anti-fungal, anti-HIV, proteinase inhibitor, anti-mycobacterial, anti-helmintics, anti-inflammatory, cytotoxic and anti-cancer characteristics of cyanobacteria. Based on nine cyanobacterial spp. Anabaena variabilis, Anabaena fertilissima, Nostoc muscorum, Nostoc punctiforme, Nostoc linckia, Nostoc commune, Spirulina platensis, Westiellopsis prolifica and Hapalosiphon sp., monograph provides information regarding application of cyanobacteria. All the experiments are represented in a simple language with explanatory diagrams. The volume also provides a glossary of technical terms used and about more than 200 references and index are in the end for the convenience of reade The book would be useful for the research students and teachers of the universities and colleges who want to study microbiology, medicine and pharmaceutical sciences with respect to antibacterial effects. It will also be useful for the pharmaceutical industries for research and development (RD) related to drug discovery. The book would be useful for the research students and teachers of the universities and colleges who want to study microbiology, medicine and pharmaceutical sciences with respect to antibacterial effects. It will also be useful for the pharmaceutical industries for research and development (RD) related to drug discovery.